When searching for the right end mill, it can be difficult to find the one that meets your specific needs. Fortunately, our guide will provide you with all the information needed to choose the best end mill for your application.
Identify Your Cutting Requirements.
An essential first step when selecting the right end mill is to identify your cutting requirements. Consider the material you are cutting, including its hardness and strength, as well as the depth of cut, tool diameter, and cutting speed. This information will help you select an end mill size that can handle the job efficiently while providing superior results.

Select an End Mill Shape and Flute Count.
When selecting your end mill, one of the most important considerations is the shape and flute count. Different types of cutting tasks will require different shapes and flute counts. For example, larger tool diameters tend to provide stronger cuts which can withstand large depth of cut values in tough materials such as stainless steel or titanium. On the other hand, tiny flutes work better for machining aluminum, brass, or plastic to create clean surfaces with minimal material removal.
Choose the Appropriate Shank Type and Size.
The shank is the cylindrical ruler of your end mill and will determine the type of tool holder and machine you can use. Choosing an appropriate shank size for your end mill is important as it will impact the amount of torque and feed rate the cutting tool can withstand. Consider the material being machined, flute count, and diameter; a proper balance between these factors will increase life expandsion and performance. Common shank sizes are 1/4”, 3/8”, and 1/2” but many end mill manufacture carry more options depending on your application needs.
Consider the Tool Type, Coating, and Geometry Options.
After reviewing the shank and material type, it’s important to consider the geometry of your end mill including the number of flutes, chamfer length, helix angle, radial rake angle, and axial rake angle. These determine how the cutting action with interact with the material being machined. Further customization is possible when selecting a specific coating or treatment to improve hardness, lubricity, and heat resistance; particularly for aluminum applications. Different tool type have different coatings that enhance chip evacuation and protect against heat fracture such as diamond black coating or titanium nitride (TiN) coating which are more durable than an uncoated end mill.
Determine the Helix Angle of the Cutter.
The helix angle of an end mill is the angle formed between the cutting surface and the axis of rotation. It can range from zero to up to 45 degrees. Lower helix angles are better for plunge cutting operations while higher helix angles are better for ramping applications. This angle determines the cutting forces, chip load per tooth, feed rate, and ultimately the quality of your finished machining outcome. When selecting an end mill for your application, make sure the helix angle matches your specific needs.